Breech-bolt lock for firearms



G. HAMMOND.

BREECH BOLT LOCK FOR FIREARMS.

APPLICATION FILED DEC. 1. 1917.

Patented Dec. 21, 1920.

INVEN TOR.

'PAT'T GRANT HAMLIVIOND, OF NEVI HAVE'N, CONNECTICUT, ASSIGNOR OFONE-THIRD T0 ALVA G. WASHB'UENE, 0F PITTSFIELD, MASSACHUSETTS, ANDONE-THIRD TO FREDERICK G. CRANE, OF DALTON, MASSEBI'LUSETTS.

BBEECH-BOLT LOOK FOR FIREARMS.

Specification of Letters Patent.

Patented Dec. 21, 1920.

Application filed December 1, 1917. Serial No. 204,922.

To all whom it may concern:

Be it known that 1, GRANT HAMMOND, a citizen of the United States,residing at New Haven, in the county of New Haven and State ofConnecticut, have invented a new and Improved Breech-Block Lock forFirearms, of which the following is a specification.

My invention relates to the class of devices that are employed forretaining a breech-bolt in the receiver of a firearm, and an object ofmy invention, among others, is to provide a lock that shall be secureagainst accidental release while at the same time being readily operatedto release the breech bolt when desired.

One form of device embodying my invention and in the construction anduse of which the objects herein set out, as well as others, may beattained, is illustrated in the accompanying drawings, in wh1ch- Figurel is a view in side elevation of the upper rear portion of a firearmembodying my invention with parts broken away to show construction.

.Fig. 2 is a top plan view of the same with parts broken away to showconstruction.

Fig. 3 is a rear end view of the receiver and breech-bolt.

Fig. 4 is a detail view in cross section through the breech-bolt andreceiver on plane denoted by dotted line 1-4 of Fig. 1.

Fig, 5 is a detail perspective view, scale enlarged, of the lockingblock.

Fig. 6 is a detail front end view of the breech-bolt.

Fig. 7 is a detail view, scale enlarged, in section of a fragment of theupper rear end of the firearm.

Fig. 8 is a detail side view of the spring supporting rod.

Fig. 9 is a detail view, scale enlarged, of a fragment of thebreech-bolt showing the means for retaining the breech-bolt compressionspring in place.

My invention, illustrated and described herein, relates particularly tothe means for retaining the breech-bolt in place in the receiver of afirearm, and, therefore, only so much of the firearm as is necessary toan understanding of my invention is illustrated in the drawings herein,and while the device forming the subject matter of this application isnot necessarily confined to any particula'r type of firearm, yet it isreadily applied to a firearm of the type illustrated and describedherein.

In the accompanying drawings the nufront portion of the frame has atrigger 17 pivotally mounted therein.

An opening 18 extends through the receiver from end to end, a barrel 13being secured in any suitable manner within the front end of thisopening, and a part of said opening back of said barrel comprisingabreech-bolt chamber 19 within which a breech-bolt 20 is slidablymounted. Any suitable connection between the trigger 17 and hammer 15may be employed for controlling the operations ofthe latter, and anydesired means for controlling movements of the breech-bolt 20 may beutilized.

The breech-bolt 20 is generally of round shape in cross section as shownin Fig. 4 of the drawings, and it is provided with a firing pin 21 thatmay be of any ordinary form and construction, said firing pin extendingthrough, or substantially through, the breech-bolt and havingthe usualparts within the breech-bolt for effecting its operation.

A breech-bolt actuating spring recess 22 is formed partially in the topof the wall of the opening in the receiver 12 and partially in the upperpart of the breech-bolt, said recess containing a breech-bolt actuatingspring 23. A lip 24 at the front end of the breech-bolt comprises theend wall of the recess 22 and the spring 23 thrusts with one end againstsaid lip and with its opposite end against a shoulder 25 upon a springsupporting rod 26, which rod extends through said spring and into thelip 24 at tom 30 of a groove in a retaining block 31. This retainingblock is of a size to slidably fit within a hole 32 extending laterallythrough the upper part of the receiver near its rear end, a lip 33 onthe block limiting its inward movement in said hole. The block is alsocut-away to provide shoulders 3435 that are received against a stop pin36 fixed in an opening extending preferably from a rear sight groove 37into the hole 32, as clearly shown in Fig. 7 of the drawings.

A spring supporting rod retaining plate 38 is formed to fit within arecess 39 in the rear end of the breech-bolt, said recess extending intothe receiver as shown in Fig. 3 of the drawings. This plate has a hole40 through which the rear end of the rod 26 constituting a thumb piece41 extends.

The plate 38 is held in place as by means of a firing pin sleeve 42 thatis preferably an integral projection from the plate 38 and that extendsinto the rear end of the breechbolt, as shown in Figs. 1 and 9 of thedrawings, the back end 43 of the firing pin, when it is in its rearwardposition, extending through said sleeve and plate. The plate 38 may beheld in place in any suitable manner, as shown herein a pin 44 extendingthrough the breech-bolt and laterally into a groove in the bottom of thesleeve.

From the above description taken in connection with the accompanyingdrawings it will readily be seen that when it is desired to remove thebreech-bolt from the receiver a pressure upon the thumb piece 41 willmove the rod 26 inward sufiiciently to remove the lip 29 from within therecess in the retaining block 31, and this release of the retainingblock will enable it to be moved out of the breech-bolt chamber, inwhich position it will not act as an obstruction to the removal of thebreech-bolt and the latter may be taken rearwardly out of the receiver,together with. the rod 26 and the spring 23, the latter still undercompression. The pin 36 will prevent the block 31 from being pulledentirely out of its hole in the receiver. WVhen the block 31 is in placeit acts as an abutment for the rod 26 that receives thev pressure of thespring 23 caused by the pressure of the lip 24 when the breech-bolt ismoved backwardly in the receiver under forces generated by the gases ofexplosion.

The construction herein illustrated and described affords extremelyefiicient means whereby the breech-bolt may be readily removed andreplaced without the necessity of relieving compression springs of theirforce, or of restoring the compression to such springs, in the operationof removing and inserting the breech-bolt. A firearm embodying my withindescribed invention is, therefore, peculiarly applicable to the cleaninof parts of the mechanism and especia y to the cleaning of. the barrelfrom the breech end thereof, the mechanism being readily removed forsuch purpose and the chamber being free and unobstructed from the rearend of the firearm into the breech portion of the barrel, and thebreech-bolt being readily reinserted.

A breech-bolt lock 45 is located in an opening through the bottom of thebolt into the chamber containing the firing pin, the head of said boltextending into a locking recess 46 in the bottom wall of the receiver.Said bolt lock is held in its locked position as by means of a spring 47located within the bolt lock and thrusting against a spring seat 48 thatrests against the firing pin in the bottom of the opening in which thebreech-bolt lock is located. The breech-bolt lock and the spring seatare both notched to receive a body 49 of the firin pin, this part of thebody being preferabl y flattened on opposite sides and the notch beingof a depth to permit a limited movement of the breechbolt lock laterallyof the firing pin. The head of the breech-bolt lock is recessed toreceive the cam shaped end 50 of a bolt lock actuator 51 that will bemounted and operated in any desired manner, Such actuator, as will beplainly seen from Fig. 1, engaging the cam shaped side of the recess andforcing the breech-bolt lock '45 upwardly against the tension of itsspring from engagement with its opening in the receiver when the latter,together with the breech-bolt are thrust backwardly by the forces of thegases of explosion and sweep the lock 45 over the top of the actuator51, in a manner well known in devices of this class.

The body 49 of the firing pin has a looking notch 52 that is of a widthto receive the breech-bolt lock 45, said notch 52 being formed toreceive said lock, and the body adjacent to said locking notch being, inthe backward position of the firing pin, located to prevent movement ofthe locking bolt, as 110 shown in Fig. 1 of the drawings. Said lockingbolt, when it is in its position to unlock the breech-bolt, thus acts asa look for the firing pin and the firing pin, when it is in its rearwardposition in the breech-bolt, acts to pre- 115 vent unlocking movement ofthe breech-bolt lock. The firing pin is of a length less than the lengthof its opening through the breechbolt and when it is locked by thebreech-bolt lock, both its ends being within the breech- 120 bolt, thefiring pin cannot be actuated to explode a cartridge, and this lockingtakes place during all of the time when the breechbolt is unlocked, and,likewise, the firing pin acting as a lock for the breech-bolt lock, the125 breech-bolt cannot be released when the firing pin is in itsoperative position. The breech-bolt lock and firing pin thus act assafety devices one for the other the breechbolt lock holding the firingpin in a safety 130 position when the breech-bolt is unlocked and thefiring pin preventing unlocking movement of the breech-bolt lock whenthe firing pin is in an operative position.

In accordance with the provisions of the patent statutes, I havedescribed the principles of operation of my invention, together with thedevice which I now consider to represent the best embodiment thereof;but I desire to have it understood that the device shown is onlyillustrative and that the invention may be carried out by other means.

I claim- 1. A firearm including a frame having a breech-bolt chambertherein, a breech-bolt located in said chamber and having a springrecess, a spring located in said recess and compressed therein entirelyby parts carried by the breech-bolt when the latter is removed from theframe, means supported by the frame for opposing thrust of said spring,said means being movably mounted to re lease said spring from pressurethereagainst, and means located at the rear end of the breech-bolt formaintaining compression of said spring when the breech-bolt is removedfrom the frame.

2. A firearm including a frame having a breech-bolt chamber therein, abreech-bolt located in said chamber and having a spring recess, a springlocated in said recess and compressed therein entirely by parts car riedby the breech-bolt when the latter is removed from the frame, a springsupport ing rod, means supported by the frame for resisting the thrustof the spring against said rod, said means being movably mounted torelease said spring from pressure thereagainst, and means located at therear end of the breech-bolt for retaining said rod in position when thebreech-bolt is removed from the frame.

3. A firearm including a frame having a breech-bolt chamber therein, abreech-bolt located in said chamber and having a spring recess, a springlocated in said recess and compressed therein entirely by parts carriedby the breech-bolt when the latter is removed from the frame, meanssupported by the frame for opposing the thrust of said spring, saidmeans being movably mounted to release said spring from pressurethereagainst, and a plate secured to the rear end of the breech-bolt toretain said spring in place when the breech-bolt is removed from theframe.

4. A firearm including a frame having a breech-bolt chamber therein, abreech-bolt located in said chamber and having a spring recess, a springsupporting rod located in said recess, a spring located on said rod insaid recess and compressed therein entirely by parts carried by thebreech-bolt when the latter is removed from the frame, means supportedby the frame for resisting thrust of the spring against said rod, saidmeans being movably mounted to release said spring from pressurethereagainst, and a plate secured to the end of the breech-bolt to holdsaid rod in position when the breechbolt is removed from the frame.

5. A firearm including a frame having a breech-b0lt chamber therein, abreech-bolt located in said chamber and having a spring recess, a springlocated in said recess and compressed therein entirely by parts car riedby the breech-bolt when the latter is removed from the frame, a springsupporting rod, and a plate secured to the rear end of the breech-boltto hold said rod in place, said plate having a hole through which theback end of said rod projects.

6. A firearm including a frame having a breech-bolt chamber with arecess in the upper wall of said chamber, a breech-bolt located in saidchamber and having a spring recess, a spring located in said recess andcompressed therein entirely by parts carried by the breech-bolt when thelatter is removed from the frame, means supported by the frame forresisting the thrust of said spring, said means being movably mounted torelease said spring from pressure thereagainst, and a rod located in therecess in the breech-bolt and secured therein to retain said springunder compression when the breech-bolt is removed from the chamber.

7. A firearm including a frame having a breech-bolt chamber therein anda recess opening out of said chamber, a breech-bolt located in saidchamber and having a spring recess, a spring located in said recess andcompressed therein entirely by parts carried by the breech-bolt when thelatter is removed from the frame, a spring supporting rod located insaid recess, means supported by the frame to resist the force of saidspring, and a plate closing the rear end of said recess in the frame andbreech-bolt and having an opening through which the rear end of said rodprojects.

8. A firearm including a frame having a breech-bolt chamber therein, abreech-bolt located in said chamber and having a spring recess, a springlocated in said recess and compressed therein entirely by parts carriedby the breech-bolt when the latter is removed from the frame, means forretaining the spring in said} recess when the breech-bolt is removedfrom the firearm, and a sliding member supported by the frame to resistthe force of said spring and movable to permit removal of the breechboltfrom the frame.

9. A firearm including a frame having a breech-bolt chamber therein, abreech-bolt located in said chamber and having a spring recess, a springlocatedin said recess, a spring supporting rod located in said recess,

a member slidably mounted in the frame to engage said rod and supportthe thrust of the spring, and means for retaining said rod in place inthe breech-bolt when the latter is removed from the frame.

10. A firearm including a frame having a breech-bolt chamber therein, abreech-bolt located in said chamber and having a spring recess, a springlocated in said recess, a spring support located in said recess andhaving a lip, a member slidably mounted in the frame and having a recessto receive said. lip and to support the thrust of the spring gainst saidrod, and means for moving said rod to release said lip from engagementwith said member.

11. A firearm including .a frame having a breech-bolt chamber therein, abreech-bolt located in said chamber and having a spring recess, a springlocated in said recess, a spring rod to support the thrust of saidspring and having a cut-away part with a lip thereon, a member slidablymounted in the frame and having a recess to receive said lip, and meansfor holding said rod in place when the breech-bolt is removed from theframe.

12. A firearm including a frame having a breech-bolt chamber therein, abreech-bolt located in said chamber and having a spring recess, a springlocated in said recess, a rod located in said recess to receive thethrust of said spring and having a cutaway part forming a beveled lip, asliding block movable transversely in the frame and having a recess toreceive said'lip, and means for securing said rod in place.

13. A firearm including a frame having a breech-bolt chamber therein, abreech-bolt located in said chamber and having a spring recess, a springlocated in said recess, a spring rod located in said recess to resistthe force of said spring, said rod being cut-away at its upper partforming a lip, a block slidably mounted in the frame transverselythereof and having a recess to receive said lip, and a plate secured tothe rear end of the breech-bolt to hold said rod in place and having anopening to receive the end of said rod that projects through the plate.

14. A firing mechanism for a firearm including a breech-bolt movablymounted in a breech-bolt chamber in the firearm, a forked lock to retainthe breech-bolt in its closed position, means for operating said look, afiring pin extending between the forks of said lock and movably mountedin a hole extending through the breech-bolt and having a cross-wisegroove to receive the body of said look at the base of said forks toretain the firing pin in inoperative position, and cooperating meansupon said lock and firing pin to hold said lock in its locked position.

15. A firearm including a frame having a breech-bolt chamber therein, abreech-bolt located in said chamber and having a spring recess, a membermovably supported by the frame and independently of the breech-bolt, aspring located in said recess and supported by said member when thelatter is in one position and by the breech-bolt when said member is inanother position, and means located at the rear end of the breech-boltto receive the thrust of said spring when the breech-bolt is removedfrom the frame.

, GRANT HAMMOND.

